The complement system serves as an important source of chemotactic factors for tumor cells. Existing evidence indicates that a fragmentation product of C5a is the main source of chemotactic factor. The proposed study will have three overall goals. These will be to 1) examine the chemotactic factor-treated cells for alterations in physiologic function; 2) probe the structure of the C5a-related chemotactic factor and the receptors on the cells for the C5a chemotactic factor and 3) determine if treatment of animals with the chemotactic factor can alter the pattern of tumor cell localization in those animals.